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1  Using Arduino / Motors, Mechanics, and Power / Re: Stepper motor setup for Unimat Classic type tools. on: February 16, 2014, 03:02:09 am
Cnc routing of acrylic can be difficult to get acceptable results and tool coolant is essential.
Post routing the acrylic will also need annealing, especially if you want to glue it.

I tend to "Lap" the service to get a perfectly smooth finish before polishing and glueing. The device will be mostly for turning acrylic but semi accurate routing will be wonderful.
2  Using Arduino / Motors, Mechanics, and Power / Re: Stepper motor setup for Unimat Classic type tools. on: February 15, 2014, 10:08:39 am
A stepper is unlikely to be the correct choice for driving a tool bit. Among other things 300rpm is quite fast for a stepper motor. And they are likely to be too "jerky" to give a good finish.

A regular DC motor with reduction gearing would be much more suitable. Machine tools with speed control usually have a system to maintain a constant speed as the load on the tool changes. That probably requires some sort of feedback mechanism.

Can you provide a link to the Unimat tool you have?

Can you explain in more detail what you want to do. Your comment about the 12000 rpm motor probably has nothing to do with multiple axis control so the whole post is a bit confusing. This is essential before any guidance about types of motor etc can be given.
Thats wierd, I read that in the nema 17 specs on ebay but I havent seen it on any other post.
Also the power motor of the tool runs at 12,800 66w 12v.
I was hoping that a 300rpm stepper existed and was better the a geared motor running at 300rpm.

You will need stepper motors if you plan to control tool positions and you should use proper stepper motor drivers such as the Pololu A4988 (which may or may not suit your motors).

A Mega or Uno can easily control 3 axes but a lot may depend on how much computation is needed to interpret the movement instructions.

Are you aware of GRBL (use Google).

I looked at the ramps board should I decide to go cnc.
Nope, cnc is new stuff for me to explore. but just googled ans started reading.
The MKIII Uno is in the last place you left it (unless you employ a cleaner).
Thanks, now I just wish I could remember where that was.
3  Using Arduino / Motors, Mechanics, and Power / Stepper motor setup for Unimat Classic type tools. on: February 15, 2014, 07:19:16 am
I suppose I could use a motor or double gear setup but ...

I have an arduino Mega 25** and the arduino motor shield. I have purchased one of these small multi-role tools for working on acrylic but they don't seam to be able to go below 12000 rpms the idea of adding a stepper motor to the setup makes me think that it could be a worth while upgrade but I have a few questions.

1, What sort of stepper would I need to run down to 300 rpm's and what kind of force can I expect from a stepper at this speed.
2, will the motor shield be able to handle the job I intend it to do?
3, where on earth did I put my MKIII uno?
4, would the mega be able to drive 3 axis?
5, should I dump the shield and use the Poulolo drivers and if so.
6 what combination should I get?
4  Using Arduino / Microcontrollers / Re: Using arduino's atmega328 standalone on: February 01, 2014, 02:04:15 am
Yes and it's normally known as a "Bare Bones" system.

Basically just the chip, required support components and components that make up the circuitry.
5  Using Arduino / Microcontrollers / Re: Standalone 3.3v Atmega 328p - Do I need a Crystal or Resonator? on: January 21, 2014, 04:11:49 pm

A risk with LiPo batteries is draining them too death.  You will need a cutoff.  Depending on what else is in the circuit you may be able to put the processor into Power Down sleep mode (after turning everything off) when the battery voltage reaches the floor.

This article has details about draining (and charging)...

The problem is not with draining them to death, it causing voltage to drop so low that a chemical trip cuts in. There are ways to revive them and restore them but it can be risky if done wrong! (I have revived 3 lipo's so far but they were all only a year old when they tripped!)
6  Using Arduino / LEDs and Multiplexing / Re: TLC5940, problems with leds staying on after they are faded on: December 14, 2013, 03:22:12 pm
Not necessaries connected to your problem but your missing the bypass capacitors across the TLS's + and - line. (VSS & VDD)
7  Using Arduino / General Electronics / Re: m2 memory card instead SD card on: October 16, 2013, 02:40:16 pm
What is a "m2 memory card" ?

Memory Stick Micro!

Miniature version of the sony memory stick and memory stick pro duo!

I doubt it as there different formats and shapes!
8  Using Arduino / Audio / Re: fully assmbled wave shield on: September 08, 2013, 04:11:37 am
Honestly, if you follow the instructions, the Adafruit wave shield is very easy to assemble.
One could even go so far as to say that its an ideal beginners project!
9  Using Arduino / Displays / Re: Pinout for 16x2 LCD on: August 18, 2013, 04:02:26 am
Its probably one of the Hitachi HD44780 LCD controller based modules.
Remove it from the other board and you should find it easer to identify.
10  Topics / Robotics / Re: BBC Turtle Clone? on: July 31, 2013, 04:48:53 am
Some interesting information being posted here.

I have an original BBC turtle robot in my shed and surprised how solidly it was built.

I have an arduino +motor shield but never sat down to use it.
11  Using Arduino / Audio / Re: sine, wave, saw-tooth, triangle wave generator code needed on: June 25, 2013, 03:13:41 pm
Without knowing more, It looks like the OP is building the generator input stage for a SID chip
12  Topics / Home Automation and Networked Objects / Re: replacing arduino with alternative in specific project on: June 23, 2013, 01:51:02 am
Are you meaning Arduino as in a flu prebuilt unit or Arduino as in Atmega328p bare bones components.
13  Using Arduino / LEDs and Multiplexing / Re: Expand PWMs output with HIGH CURRENT (alternatives to TLC5940) on: June 23, 2013, 01:35:34 am
In alot of the earlier projects people used tip120 darlington transistors.
According to ebay there rated at 5A.

I understand that loads of them are not as nice as a single package chip, but there cheep and easy to get hold off.
14  Using Arduino / Networking, Protocols, and Devices / Re: Android + Arduino issues (over USB) on: June 08, 2013, 10:08:47 am
Have you uploaded the appropriate arduino code to the arduino first?
15  Using Arduino / General Electronics / Re: Begginer Electronic Book? on: April 21, 2013, 09:34:43 am
I managed to snag most of Mims III's radio shack books when Tandy (Radioshack UK) closed. these were how I learnt along with 2 equally old model railway electronics books.
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